Shoppers spend as petrol prices fall

Falling petrol prices and talk of an interest rate cut led to a big jump in retail sales in the five days leading up to Christmas.

Sales were 13 percent higher than for the same period a year ago, a national survey found.

Boxing Day retail sales are expected to top last year's figure of $1.9b. (9NEWS) ()

The BDO Australian Retail Index also shows shoppers spent up big in the last weekend before Christmas yesterday.

"Falling petrol prices, very low interest rates and talk of a rate cut are giving consumers a lot of confidence to go out there and spend over the Christmas period," BDO National Retail Lead Partner Simon Scalzo said.

"We are seeing a significant increase in sales from retailers across Australia."

This boded well for the annual Boxing Day sales, with the sector expecting receipts to hit $2.1 billion, eclipsing last year's $1.9 billion.